Cooling jacket for machine gun barrels



' p 27, 1932- R. c. COUPLAND COOLING JACKET FOR MACHINE GUN BARRELIS Filed Jan. 9, 1931 [III/Illa VIII I,IIIIIIIIIIIIIIIIIIIII v I 2 K, I n\ INVENTOR. Richard ELEuu land ORM Patented Sept. 27, 1932 B-IGHARD C. GOU'PLAND, OF THE UNITED STATES ARMY, OF NORFOLK, VIRGINIA oooLineJAcKE'r non MACHINE GUN BARRELS Application filed January 9, 1931. Serial No. 597,613.

5 (GRANTED UNDER THE Ac'r or MARCH 3, 1883,1125 AMENDED APRIL 30, 1928; 370 o. s. 757

The invention described herein may be manufactured and used by or for the Government for governmental purposes, without the payment to me of any royalty thereon The subject of this invention 1s a cooling jacket for machine gun barrels.

The general practice in cooling machine gun barrels consists in surroundlng the barrel with a liquid and inasmuch as the barrel m has a reciprocatory movement it is necessary to provide a packed oint to prevent leakage.

In the present invention it is proposed to provide the cooling jacket in the form of an annular casing, the liquid in the acket being out of contact with the gun barrel. By virtue of this arrangement the packed olnts are eliminated and the jacket may be readily attached to and detached from the gun without disturbing the barrel. 20 The invention is further characterized by a novel method of venting the jacket when r the vapor pressure reaches a predetermined value.

With the foregoing and other objects in 25 view, the invention resides in the novel arrangement and combination of parts and in the details of construction hereinafter described and claimed, it being understood that changes in the precise embodiment of the in 210 vention herein disclosed may be made within the scope of what is claimed without departing from the spirit of the invention.

A practical embodiment of the invention is illustrated in the accompanying drawing, wherein:

.Fig. 1 isa view in side elevation of a machine gun equipped with the improved cooling jacket;

Fig. 2 is a plan view thereof; to Fig. 3 is a longitudinal sectional view of the cooling jacket;

. Figs. 4 and 5 are detail sectional views on therespective lines of Fig. 2.

Referring to the drawing by numerals of L5 reference .rel consists of an annular casing formed of rear cap 13 is formed with spaced concentric a block 18 being wholly within the tube and the j There is shown a machine gun comprising areceiver and a barrel 6 supported in bearings f7-7 of the receiver and attached to a reciprocally mounted member 8.

"The cooling jacket 9 surrounding the baran outer corrugated tube 10 and aninner tube 11 maintained in spaced relation by a front end cap 12 and a rear end cap 13. The

annular extensions 14 and 15 'fitting respectively on the inside and the outside of an annular lip 16 of the receiver. The jacket is securely attached to the receiver by means of a threaded connection 17 which in the present instance is associated with the inside extension 14.

Secured to the outer tube 10 adjacent. its extremities are a pair of blocks, the rear block and to. an inlet passage 27 in the rear block. This arrangement permits the vapor of the llquid to be exhausted from the acket irrespective of the inclination of the jacket.

Bell crank levers 28 and 29 respectively mounted in the rear and the forward blocks 1 18 and 19 each carries a ball valve, 28a and 29a, arranged to close the inlet passages in the blocks. A rod 30 connects the levers 28 and 29 and serves as a gravity actuator to simultaneously operate the levers.

When the jacket is in horizontal position the valves 28a and 29a will both be in the open position (Figs. 4 and 5) above the level of the cooling liquid but when the jacket is inclined the lowermost valve will be closed to prevent the liquid from entering the passages leading to the outlet passage 22. The vapors generated when the liquid becomes heated will be vented when the pressure exceeds the load on the ball valve 23.

The outer tube 10 is provided with an opening 31 for introducing the cooling liquid into the jacket and also with an opening 32 for draining the acket.

By virtue of the complete independence of the cooling jacket with respect to the barrel, either one of these members may beremoved without disturbing the other and without the necessity of draining the liquid from the jacket. V

The arrangement is particularly adapted for the employment of anagent having a high boiling point such as ethylene-glycol or diethylene glycolp Therpurpose in view is to permit a high rate of firing and to increase :the number of rounds fired before the agent 'in the cooling jacket reaches a temperature of vaporization. The high difierential between the temperature of the jacket and the temperature of the atmosphere induces a considerable drop'in temperature of the agent im- 'mediately the barrel. I claim:

connecting the tubes in spaced relation, and gun-attaching means on one end cap.

2. cooling jacket for guns, comprising an inner tube adapted to fit over a gun barrel, 7 an outer tube, annular end caps connecting the tubes in spaced relation, and gun-attaching means on one end cap.

block and the valved outlet in the other block,

a bell crank lever carried by each block and arranged to close the inlet passage of said block, and a rod connecting the levers.

' 6. In a cooling jacket for guns, a casing, a

each end, an inlet passage in each block, an

outlet intone ofthe blocks, a tubeconnecting the blocks and establishing communication the valved outlet in the other block, a pivotal- 3. A cooling jacket'for guns comprising enclosed annular casing surrounding the barbetween the inlet passage in one block and the casing.

9. In combination with a gun barrel, a fluid container fitting over the barrel and being out of fluid communication withsaidbarrel.

10. In combination with a gun barrel, a cooling jacket including an inner tube fitting around the barrel and slidable relative there RICHARD G. COUPLAND.

upon cessation of firing through V 1. A cooling jacket for guns, comprising an lnner tube'adapted to fit over a gun barrel, -a corrugated outer tube, annular end caps i block on the inside wall of the casing adjacent 

